1. Field of the Invention
The present invention relates to an impact-resistant apparatus, such as a portable computer, enabled to abort a predetermined operation based on an output from an impact sensor.
2. Background
In a hard disk drive, data is read and written generally in such a manner that a read/write head, fixed on a tip of an access arm, is positioned at each track on a rotating disk by moving the access arm. Accordingly, when an impact is applied to the hard disk drive while writing data, the head may hit the disk or deviate from a target track, resulting in the possibility of data damage or data loss.
Therefore, methods and apparatus have been developed to combat this problem. In certain known hard disk drives for notebook-type personal computers (hereinafter, referred to as a “notebook PC”), data is prevented from being damaged or lost by providing an impact sensor inside the hard disk drive or on the main body of the notebook PC. When an impact with at least a predetermined magnitude is detected, writing on the disk is immediately aborted, or alternatively, the head is withdrawn after writing is aborted. Writing is continued after the impact subsides; see, for example, Japanese Unexamined Patent Publication No. Hei 11-45499
However, it has been revealed that, according to such a conventional technology, high impact resistance is demonstrated when a device falls from a high position, whereas the impact resistance is not as effective when the device falls from a relatively low position at a height of around 20 to 30 mm. Specifically, when a device falls from a high position (a height of around 100 mm), data is not damaged because a write operation is aborted beforehand based on an output from an impact sensor. However, in a device in which data damage or the like is caused due to a fall from a low position, it has been found that an off-track write occurs due to the vibration of a head caused by an impact during a write operation. The off-track write is an event of writing on an adjacent track.